Synthesis and characterization of ionic, thermotropic liquid-crystalline polyesters

摘要

Although liquid-crystalline polymers (LCPs) have been widely used as high-performance polymers, two major problems need to be addressed for their extensive use in modern science and technology. The first problem is their poor transverse and compressive properties in contrast to very high axial properties that are typically one or two order(s) of magnitude lower, both of which are inherent to the highly uniaxial orientations of LCPs. The second one is their poor miscibility and adhesion with thermoplastic polymers, when LCPs and thermoplastic polymers are mixed to produce polymer blends for the improvement of their mechanical properties. Both the problems are principally related to the weak intermolecular interactions (van der Waals forces and/or hydrogen bonding) either in an LCP itself or in an LCP/polymer blend, which are in contrast to the strong covalent bonds along the direction of polymer chains.